6 Waste Management Implications
6.1 Legislation, Standards and Guidelines
6.2 Description of the Environment
Figure 6.1 Proposed
Works Area and Sediment Sampling Locations
Appendix 6.1 Sediment
Sampling and Testing Plan
Appendix 6.2 Laboratory
Testing Results
Appendix 6.3 Summary of
the Chemical and Biological Screening Tests results
6.1 Legislation, Standards and Guidelines
6.1.1 General
6.1.1.1 The relevant legislation related to the Study for the assessment of waste management implications include:
·
Environmental Impact Assessment
Ordinance (EIAO) (Cap. 499), including Technical Memorandum on Environmental
Impact Assessment Process (TM-EIAO), Annex 7 and Annex 15;
·
Waste Disposal Ordinance (WDO)
(Cap. 354) and subsidiary regulations;
·
Dumping at
Sea Ordinance (Cap. 466);
·
Land (Miscellaneous Provisions)
Ordinance (Cap. 28); and
·
Public Health and Municipal
Services Ordinance (Cap. 132) - Public Cleansing and Prevention of Nuisances
Regulation.
6.1.1.2
Under the WDO,
some of the subsidiary regulations are relevant to the present EIA, including:
·
Waste Disposal (Chemical Waste)
(General) Regulation (Cap. 354C); and
·
Waste Disposal (Charges for
Disposal of Construction Waste) Regulation (Cap. 354N).
6.1.2 Waste Disposal Ordinance
6.1.2.1 The WDO prohibits any unauthorised disposal of wastes. Construction waste, defined under Cap. 354N of the WDO, refers to a substance, matter or thing which is generated from construction works. It includes all abandoned materials, whether processed or stockpiled or not, before being abandoned, but does not include sludge, screenings or matter removed or generated from desludging, desilting or dredging works.
6.1.2.2 Under the WDO, wastes can only be disposed of at designated waste disposal facilities licensed by Environmental Protection Department (EPD). Breach of this Ordinance can lead to a fine and/or imprisonment. The WDO also stipulates the requirements for issuing licenses for the collection and transportation of wastes.
6.1.3 Waste Disposal (Chemical Waste) (General) Regulation
6.1.3.1
Under the WDO, the Waste
Disposal (Chemical Waste) (General) Regulation provides regulations for
chemical waste control, and administers the possession, storage, collection,
transport and disposal of chemical wastes.
EPD has also issued a ‘guideline’ document, the Code of Practice on the
Packaging, Labelling and Storage of Chemical Wastes (1992), which details how
the Contractor should comply with the regulations on chemical wastes.
6.1.4 Waste Disposal (Charges for Disposal of Construction Waste) Regulation
6.1.4.1
Under the Waste Disposal
(Charges for Disposal of Construction Waste) Regulation, construction waste
delivered to a landfill for disposal must not contain more than 50% by weight
of inert material. Construction waste delivered to a sorting facility for
disposal must contain more than 50% by weight of inert material, and
construction waste delivered to a Public Fill Reception Facilities for disposal
must consist entirely of inert material.
6.1.5 Dumping at Sea Ordinance
6.1.5.1 According to the Dumping at Sea Ordinance, a permit from EPD is required if any waste producer intends to dump materials from vessels to designated marine dumping areas. The Authority will consider a number of factors including sources and nature of materials to be dumped, dumping rates, need for inspection / testing, water pollution avoidance measures etc before determining whether such a permit would be granted and, where deemed necessary, any conditions to be complied with. Breach of the requirements in the permit would result in a fine and/or to imprisonment.
6.1.6 Land (Miscellaneous Provisions) Ordinance
6.1.6.1 The inert portion of Construction and Demolition (C&D) materials may be taken to public filling facilities including public filling area, public filling barging points and stockpiling areas. These facilities usually form part of land reclamation schemes and are operated by Civil Engineering and Development Department (CEDD). The ordinance requires Dumping Licenses (to be issued by CEDD) to be obtained by individuals or companies, who deliver inert C&D materials to the public filling facilities.
6.1.7 Public Cleansing and Prevention of Nuisances Regulation
6.1.7.1 This regulation provides control on illegal tipping of wastes on unauthorised (unlicensed) sites.
6.1.8 Other Relevant Guidelines
6.1.8.1 The documents and guidelines listed in Table 6.1 are also related to waste management and disposal during construction:
Table 6.1 Other Relevant Documents and Information
|
Bureau / Department |
Documents / Guidelines / Technical Circulars |
|
Environmental Protection Department (EPD) |
· Waste Disposal Plan
for Hong Kong (December 1989) · Waste Reduction
Framework Plan, 1998 to 2008 · A Policy Framework
for Management of Municipal Solid Waste (2005-2014), (December 2005) · Code of Practice on
the Packaging, Labelling and Storage of Chemical Wastes (1992) ·
A Guide to the Chemical Waste Control Scheme (2016) ·
A Guide to the Registration of Chemical Waste
Producers (2016) · Monitoring of Solid
Waste in Hong Kong (2018) |
|
Civil Engineering and Development Department (CEDD) |
· Project
Administration Handbook for Civil Engineering Works, 2018
Edition |
|
EPD / CEDD |
· New Disposal
Arrangements for Construction Waste (1992) |
|
Development Bureau (DEVB) |
· Works Branch
Technical Circular (WBTC) No. 2/93, Public Dumps · WBTC No 2/93B,
Public Filling Facilities · WBTC No. 16/96, Wet
Soil in Public Dumps · WBTC Nos. 4/98 and
4/98A, Use of Public Fill in Reclamation and Earth Filling Project · WBTC No. 12/2000,
Fill Management · WBTC No. 19/2001,
Metallic Site Hoardings and Signboards · WBTC No. 12/2002,
Specification Facilitating the Use of Recycled Aggregates · Environment,
Transport and Works Bureau Technical Circular (Works) (ETWB TCW) No.
34/2002, Management of Dredged / Excavated Sediment · ETWB TCW No. 22/2003
& 22/2003A, Additional Measures to Improve Site Cleanliness and Control
Mosquito Breeding on Construction Sites · ETWB TCW No.
19/2005, Environmental Management on Construction Sites · Development Bureau
Technical Circular (Works) (DEVB TCW) No. 6/2010, Trip-ticket System for
Disposal of Construction and Demolition Material · DEVB TCW No. 8/2010,
Enhanced Specification for Site Cleanliness and Tidiness · DEVB TCW No. 9/2011,
Enhanced Control Measures for Management of Public Fill |
|
Planning Department (PlanD) |
· Chapter 9
Environment, Hong Kong Planning Standards and Guidelines (HKPSG) |
6.2 Description of the Environment
6.2.1.1
As discussed in Section 1, the works area of the
Project is located along the coastal area of Northeast New Territories. It
overlaps mostly with Yan Chau Tong Marine Park and partly with Plover Cove
Country Park. Lai Chi Wo Beach Site of Special Scientific Interest (SSSI) is
located at 120m to the south of the Project. The works area will cover the
entire existing Lai Chi Wo Pier of approximately 64m long and 2.5m wide. The
land use characteristics in the vicinity of the Project site are rural in
nature.
6.3.1 Identification of Possible Generation of Waste
6.3.1.1 The key construction activities which may lead to the generation of waste include:
· Carrying out site investigation works for detailed design;
· Provision of temporary berthing and mooring facilities (temporary pier) using working barge and/or steel structures supported by piles to maintain access to Lai Chi Wo through the construction stage;
· Installation of piles for the new pier; and
· Removal of temporary pier after completion of the improvement works on the existing pier.
6.3.1.2 Waste generation is expected mainly for the construction activities including provision and demolition of temporary pier and installation of piles for the temporary and new piers. As for the site investigation works, waste generation is negligible in comparison with the other construction activities.
6.3.2 Assessment Methodology
6.3.2.1 The assessment of waste management implications from handling, storage, collection, transportation and disposal of solid waste materials generated by the Project have been undertaken in accordance with Annexes 7 and 15 of the TM-EIAO.
6.3.2.2 The waste management hierarchy given below prioritises various waste management methods, that will be applied in the development of mitigation measures for waste.
·
Reuse/Recycle – Reusing and
recycling the waste on-site as well as promoting segregation of waste
materials; and
· Disposal – Disposal of any inert C&D materials to public fills as last resort.
6.3.3 Analysis of Activities and Waste Generation
6.3.3.1 The quantities, types and the activity period of the waste generation during the Project have been estimated, based on a tentative construction programme, the proposed preliminary design, and the construction methods that would minimise the generation of wastes.
6.3.3.2 The management of waste associated with the handling, transportation and disposal of wastes arising from the above estimate depends on the capacity of collection, transfer and disposal facilities.
6.3.4 Proposal for Waste Management
6.3.4.1 As discussed in Section 2, multi-prone measures have been proposed to avoid/minimise and reuse/recycle the waste generated from the Project.
6.3.4.2 Regarding waste avoidance and minimisation, the Project itself has proactively avoided the demolition of the existing pier, and hence minimises over 400m3 C&D materials generated from the demolition of the existing pier structures. Based on the current design, pier structures including deck structures and canopy will be constructed by prefabrication method as far as practicable to reduce waste generation onsite. In addition, the diameter of the piles is about 1m, which has been optimised to minimise the waste generation during the construction.
6.3.4.3 From the reuse and recycle perspectives, the deck structures of the temporary pier will be mainly composed of steel structures which could be reused and recycled after the completion of the Project. The surplus inert C&D materials generated by the Project would be reused off-site as fill materials where possible. On-site sorting will be carried out on the barge to promote segregation of waste materials. Suitable containers would be provided to temporarily store the sorted materials such as metals, timbers, plastics etc.
6.3.4.4
After considering all the
opportunities for avoidance/minimisation and reuse/recycle of waste , the waste quantities and disposal outlets are
evaluated for each type of waste. The impacts caused by handling (including
labelling, packaging and storage), collection, and reuse/disposal of wastes
have been addressed and appropriate mitigation measures have been proposed.
6.3.5 Identification and Evaluation of Waste Management Implications
6.3.5.1 The main activities which would potentially result in the generation of waste include, the construction of temporary pier and the new pier, and the demolition of temporary pier. As for site investigation works, waste generation is negligible in comparison with the major construction stages.
6.3.5.2 Different types of waste to be generated during the construction phase can be divided into the following distinct categories based on their source and compositions:
· C&D materials:
o Inert C&D materials:
§ Inert soft C&D materials (such as soil, earth and slurry);
§ Inert hard C&D materials (such as rocks and broken concrete);
o Non-inert C&D materials (such as metal, glass, steel, timber, plastics etc.):
§ Non-recyclable C&D waste (i.e. not suitable for reuse as fill materials and should be recycled before disposal at landfills);
·
Chemical wastes from
maintenance of construction plant and equipment (such as spent hydraulic oil,
waste fuel, spent lubrication oil, cleaning fluids, spent solvent and scrap
batteries);
·
General refuse (from work force
and floating refuse); and
·
Marine sediment.
6.3.5.3 The estimated amount of the types of wastes to be generated during the construction phase is summarised in Table 6.2. It should however be noted that these quantities are preliminary estimates only and would need to be further reviewed and updated as the design evolves.
Table 6.2 Estimated Amount of Different Types of C&D Materials and Wastes to be Generated during Construction Phase
|
Activities |
Approximate Quantity of C&D Material and Waste to be Generated in Bulk Volume[1],
m3 |
||||||
|
Inert C&D Materials |
Non-inert C&D Materials |
Marine Sediment |
Chemical Waste
[2] |
General Refuse (See
Table 6.3) |
|||
|
Soft C&D |
Hard C&D Materials |
Non-recyclable C&D Waste |
From Workforce |
Floating Refuse |
|||
|
Carrying out Site investigation works for
detailed design |
≤ 5 |
Nil |
Nil |
Nil |
Nil |
0.26
tonnes |
0.02
tonnes |
|
Provision of temporary pier |
195 |
Nil |
Nil |
30 |
Tens of litres/kilograms per month |
4.56
tonnes |
0.22
tonnes |
|
794 |
Nil |
Nil |
149 |
||||
|
Removal
of temporary pier |
Nil |
69 |
≤ 5 |
Nil |
|||
|
Total |
994 |
69 |
≤ 5 |
179 |
5.06
tonnes |
||
Notes:
[2] Chemical waste measured by volume (litres) includes spent hydraulic
oil & waste fuel, spent lubrication oil & cleaning fluids, and spent
solvent. Scrap batteries are measured by weight (kilograms).
C&D Materials from the Construction Works
6.3.5.4 C&D materials would be generated from the following construction activities:
· Provision of temporary pier;
· Installation of piles for the new pier; and
· Removal of temporary pier.
6.3.5.5 Referring to Table 6.2, the types of C&D materials would consist of all inert hard C&D materials, inert soft C&D materials and non-inert C&D materials.
Inert Soft C&D Materials
6.3.5.6 Among the construction activities as listed in Section 6.3.5.4, inert soft C&D materials would be generated during the following construction activities:
· Provision of temporary pier; and
· Installation of piles for the new pier.
6.3.5.8 As mentioned in Section 6.3.4.2, the piles of the proposed pier improvement works have been optimised to minimise the needs of excavation of soil during construction. In addition, the Project does not require any land-based excavation works. Thus, the in-situ generation of inert soft C&D materials have been minimised.
6.3.5.9 Among the construction activities as listed in Section 6.3.5.4, inert hard C&D materials (e.g. concrete) would be mainly generated by demolition of temporary pier.
6.3.5.10 As discussed in Section 2, in order to minimise the generation of C&D materials, the pier structures including deck structure and canopy will be constructed by prefabrication method as far as practicable.
6.3.5.11 The temporary pier might comprise a working barge, a mass concrete landing and a steel structures supported by piles. During the demolition of the temporary pier, the steel structures, which are not classified as inert hard C&D materials, will be uninstalled from the piles. The steel structures can be reused and recycled in other projects.
6.3.5.12 Inert hard C&D materials would only be generated from the demolished piles and mass concrete landing. The quantity of inert hard C&D materials to be generated is minimised to as low as approximately 69 m3 subject to the actual site conditions and detailed design.
6.3.5.13 Non-inert C&D materials include metals, timbers, packaging materials, paper etc. Some can be recycled if they are not contaminated, while the contaminated one can only be disposed of as non-inert C&D waste. As the structures of new pier will be constructed by prefabrication method as far as practicable, it is anticipated that no non-inert C&D materials (e.g. formwork using metals and/or timbers) would be arisen from the construction of structures of new pier. Among the construction activities as listed in Section 6.3.5.4, non-inert C&D waste would be generated from small portion of packaging materials which cannot be recycled, as well as during removal of temporary pier.
6.3.5.14 Non-inert C&D materials such as paper cardboard, plastic and metal containers would be used during the delivery of construction materials to the Project site for all the aforementioned construction activities. These materials would need to be recycled as far as practicable.
6.3.5.15 The Project itself would not involve any removal of vegetation cover or tree felling. Non-inert C&D materials from tree or vegetation removal is not anticipated.
6.3.5.16 For the demolition of temporary pier, the majority of the steels from the temporary pier structure could be reused and recycled for the use in other projects as much as practicable. The estimated quantity of non-recyclable non-inert C&D waste generated from the packaging materials and the demolition of temporary pier combined is expected to be negligible (≤5m3).
6.3.5.17 To facilitate reuse and recycle of non-inert C&D materials, a specific area would be allocated on the barge for on-site sorting. Suitable containers would be provided to temporarily store the sorted materials such as metals, timbers, plastics, paper etc.
Summary for C&D Materials Management
Implications
6.3.5.18 Provided that the mitigation measures are adopted, the potential environmental impacts caused by the storage, handling, transport and disposal of C&D materials are expected to be minimal. It is recommended that C&D materials should be sorted on-site. Mitigation measures to minimise potential environmental impacts are recommended in Section 6.3.7.
General Refuse
6.3.5.19 General refuse is mainly generated from construction work force during the construction period and mainly comprises food waste, waste paper, aluminium cans and plastic bottles.
6.3.5.20 Improper storage of general refuse would give rise to adverse environmental impacts in the form of windblown litter and floating refuse which would have odour and visual/water quality impacts. It would also attract pests and vermin if the storage areas are not well maintained and cleaned regularly. Therefore, disposal of waste at approved disposal facilities could avoid adverse environmental impacts.
6.3.5.21
The
work force to be deployed on site for the Project is estimated at about 5 for
site investigation and 10 for the major construction stages. Based on the generation rate of 0.65 kg/person/day, the total
refuse generated per day would be less than 6.5 kg. Therefore, it is estimated that a total of 0.26 tonnes
and 4.56 tonnes of general refuse would be generated from
work force during the site investigation and major construction stages respectively.
The detailed breakdown of estimated amount of general refuse to be generated
during construction phase is summarised in Table 6.3a.
Table 6.3a Summary of General Refuse Generated by Work Force during Construction Phase
|
Size of Work Force |
Waste Generation
Rate (kg/person/day) |
Daily Waste
Generation (kg/day) |
Duration (months) [1] |
Total Amount Generated (tonnes) |
|
|
Site Investigation |
5 |
0.65 |
3.25 |
3 |
0.26 |
|
Other Construction Stages |
10 |
0.65 |
6.5 |
27 |
4.56 |
Note:
[1]
Assume
26 working days per month.
6.3.5.22 In order to minimise the final disposal quantities of general refuse, provisions of recycle bins for different types of recyclable waste should be provided together with a general refuse bin. Arrangements should be made with the recycling companies to collect the recycle waste as required. The Contractor should implement an education programme for workers relating to avoiding, reducing, reusing and recycling general waste. Participation in a local collection scheme should be considered by the Contractor to facilitate waste reduction.
6.3.5.23 In addition, floating refuse may also be one of the waste types collected at the Project site. However, it is noteworthy that the Project itself does not intend to discharge waste to the sea or generate any floating refuse. They are brought to the Project site by water current, or by heavy rain or typhoon from the land outside the Project site. According to EPD’s Clean Shorelines Website regarding the statistics of marine refuse collected from marine parks and marine reserve by AFCD in 2019, the monthly averaged marine refuse collected from Yan Chau Tong Marine Park is 3.53 tonnes in 2019. The Project site is about 1.53ha, which approximately occupies about 0.2% of total area of Yan Chau Tong Marine Park of about 680ha. As such, the quantity of floating refuse collected at the Project site during the construction of the Project is anticipated to be as low as about 0.008 tonnes per month. It is estimated that a total of 0.02 tonnes and 0.22 tonnes of floating refuse would be collected during the site investigation and major construction stages respectively. Future contractor will be required to collect floating refuse within the Project site regularly to avoid potential waste accumulation and hygiene issues.
Table 6.3b Summary of General Refuse contributed from Floating Refuse during Construction Phase
|
Stage |
Estimated Collection of Floating Refuse at the
Project Site (tonnes/month) |
Duration (months) |
Total
Estimated Amount (tonnes) |
|
Site
Investigation |
0.008 |
3 |
0.02 |
|
Other
Construction Stages |
0.008 |
27 |
0.22 |
6.3.5.24 Provided that the mitigation measures are adopted, the potential environmental impacts caused by the storage, handling transport and disposal of general refuse are expected to be minimal. It is recommended that general refuse should be collected on a daily basis for disposal. Mitigation measures to minimise potential environmental impacts are recommended in Section 6.3.7.
Chemical Waste
6.3.5.25 Materials classified as chemical waste are listed in the Waste Disposal (Chemical Waste) (General) Regulation. The main chemical waste types arising from the construction sites may include the following:
·
Scrap batteries;
·
Spent hydraulic oils and waste
fuel;
·
Spent lubrication oils and
cleaning fluids from mechanical machinery; and
·
Spent solvent from equipment
cleaning activities.
6.3.5.26 Chemical waste may pose the following environmental, health and safety hazards if not stored and disposed of appropriately:
·
Toxic effects to workers;
·
Adverse effects on water and
land from spills; and
·
Fire hazards.
6.3.5.27
It is difficult to quantify the
amount of chemical waste as it will be highly dependent on the Contractor’s
on-site maintenance practice and the quantities of plant and vehicles utilized.
Nevertheless, it is anticipated that the quantity of chemical waste, such as
lubricating oil and solvent produced from plant maintenance, will be small and about
tens of litres per month.
6.3.5.28 Storage, handling, transport and disposal of chemical waste should be arranged in accordance with the Code of Practice on the Packaging, Labelling and Storage of Chemical Waste published by the EPD. Chemical waste should be collected by a licensed chemical waste collector and to be disposed of at a licensed chemical waste treatment and disposal facility. Wherever possible, opportunities for the reuse and recycling of materials will be taken. Mitigation measures for chemical wastes are detailed in Section 6.3.7. Provided that the handling, storage and disposal of chemical wastes are in accordance with these requirements, adverse environmental impacts are not expected.
6.3.5.29 The estimated amount of chemical waste to be generated during construction phase is summarised in Table 6.4.
Table 6.4 Summary of Chemical Waste during Construction Phase
|
Waste
Type |
Total
Amount Generated |
|
Scrap Batteries |
Tens of kilograms per month |
|
Spent Hydraulic Oil and Waste Fuel |
Tens of litres/kilograms per month |
|
Spent Lubrication Oil and Cleaning Fluids |
|
|
Spent Solvent |
6.3.5.30 Provided that the mitigation measures are adopted, the potential environmental impacts caused by the storage, handling, transport and disposal of chemical waste are expected to be minimal. It is recommended that chemical waste should be stored properly and collected by a licensed chemical waste collector. Mitigation measures to minimise potential environmental impacts are recommended in Section 6.3.7.
Marine Sediment
6.3.5.31 Among the construction activities as listed in Section 6.3.5.4. Marine sediment would only be generated during the following construction activities:
· Provision of temporary pier; and
· Installation of piles for the new pier.
6.3.5.32 As discussed in Section 2, marine bored piles with casings will be adopted to construct the foundation for the temporary pier and the new pier head. Marine sediment within the casing would need to be excavated to allow subsequently placing rebar and filling concrete within it. No sediment open dredging works are required. The works area where excavation would be carried out is shown in Figure 6.1. The quantity of excavated sediment would be largely subject to the actual geological conditions and detailed design but is preliminarily estimated to be approximately 179m3.
Sediment Sampling
and Testing Plan
6.3.5.33 Since the construction activities are anticipated to generate excavated sediment and there are no available data about the sediment condition based on a desktop study, appropriate field investigation, sampling and chemical and biological laboratory tests shall be conducted to characterise the categories of the excavated sediment and their quantities. According to Clause 3 in Appendix E of the EIA Study Brief (ESB-305/2017), the ranges of parameters to be analysed; the number, type and methods of sampling; sample preservation; chemical and biological laboratory test methods to be used shall be agreed with the Director of Environmental Protection (DEP) (with reference to section 4.4.2(c) of the TM-EIAO) prior to the commencement of the tests and document in the EIA report for consideration.
6.3.5.34 In this connection, a Sediment Sampling and Testing Plan (SSTP), as shown in Appendix 6.1, were prepared and submitted to EPD. However, it should be noted that this SSTP only serves the purpose of fulfilling the EIA Study for this Project under the EIAO and does not pre-empt what those submissions required under ETWB TC(W) No. 34/2002, such as rationale for sediment removal, SSTP, Sediment Quality Report, etc., when the sediment excavation works would take place during the construction phase.
6.3.5.35 The sediment sampling was proposed to be conducted at two sampling locations using the vibrocore sampling method at seabed level, 0.9m down, 1.9m down, 2.9m down and then every 3m to the bottom of marine sediment. A summary of the sampling information is shown in Table 6.5 and the sampling locations are shown in Figure 6.1. More details about the methodology of sampling, laboratory tests, etc. can be referenced to the SSTP in Appendix 6.1.
Table 6.5 Summary of Sampling Details at Lai Chi Wo
|
Sampling
Locations |
Sampling Method |
Sampling Depth |
Coordinates |
|
|
Easting |
Northing |
|||
|
LCW/VC1 |
Vibrocore Sample |
Vibrocore samples
collected at Seabed Level, 0.9m, 1.9m, 2.9m, and thereafter every 3m to the
bottom of marine sediment |
845235 |
843313 |
|
LCW/VC2 |
845196 |
843321 |
||
Sampling Results
6.3.5.36 Sediment samples have been collected in August and September 2019 in accordance with the approved SSTP. A total of 10 sediment samples collected, including vibrocore and grab samples, have been sent to laboratory to carry out chemical screening tests. Results indicates that all the samples collected were below the Lower Chemical Exceedance Level (LCEL), except arsenic. Based on the exceedance of arsenic concentration, 6 samples were classified as Category M and 4 samples were Category H. Biological screening test has been conducted to further classify the sediments for determining the disposal options. The results of the indicate that all Category M samples have passed the biological screening test. Therefore, 6 Category M samples would require Type 1 disposal (Open Sea Disposal (Dedicated Sites)) and 4 Category H samples would require Type 2 disposal (Confined Marine Disposal) in accordance with ETWB TC(W) No. 34/2002 – Management of Dredged/Excavated Sediment. It should be noted that separate submission, such as SSTP and Sediment Quality Report (SQR) should be submitted to the Dumping at the Sea Ordinance (DASO) team of EPD for the application for dumping permit under DASO as necessary. Summary of the chemical and biological screening tests results and the corresponding disposal options are given in Table 6.6. The laboratory testing reports are documented in Appendix 6.2 and the detail result summary is given in Appendix 6.3.
Table 6.6 Summary of Chemical and Biological Screening Results
|
Category |
No. of Samples |
Biological
Screening |
Remarks |
|
Category
L (equal to or below LCEL) |
0 |
N/A |
Type
1 – Open Sea Disposal |
|
Category
M (above LCEL but equal to or below UCEL) |
6 |
6 |
Type1
Open Sea Disposal (Dedicated Sites) |
|
Category
H (above UCEL but equal to or below 10x LCEL) |
4 |
N/A |
Type
2 – Confined Marine Disposal |
|
Category
H (above 10x LCEL) |
0 |
N/A |
Type
3 – Special Treatment/ Disposal |
Estimated Sediment Disposal
Quantities
6.3.5.37 During the construction of the temporary pier, extension of the pier deck and the provision of ramps and floating platform supported by piles, sediment will be excavated inside the steel casing during foundation works. During the demolition of temporary pier, no marine sediment would be required to be dredged or excavated.
6.3.5.38 The quantity of sediment to be generated is approximately 179 m3. The estimated quantities for various sediment categories for disposal at each construction stage have been provided in Table 6.7.
Table 6.7 Sediment to be removed in terms of category
|
Construction Stage [1] |
Quantities
(m3) |
|||
|
Category L
(equal to or below LCEL) |
Category M
(above LCEL but equal to or below UCEL) |
Category H
(above UCEL but equal to or below 10x LCEL) |
Category H
(above 10x LCEL) |
|
|
Disposal Option |
Type 1 – |
Type 1 – |
Type 2 – Confined Marine Disposal |
Type 3 – Special Treatment/ Disposal |
|
Provision of temporary pier (Q.4 2023 – Q.2 2024) |
0 |
18 |
12 |
0 |
|
Installation of piles for the
new pier (Q.2 2024 – Q.2 2025) |
0 |
91 |
58 |
0 |
|
Removal of temporary pier (Q.4 2025) |
0 |
0 |
0 |
0 |
|
Total |
0 |
109 |
70 |
0 |
Note:
[1]
During site investigation, the excavated marine sediment will be delivered to
the laboratory and no sediment would require off-site disposal.
Summary of Marine Sediment Management
Implication
6.3.5.39 Provided that the mitigation measures are adopted, the potential environmental impacts caused by the storage, handling, transport and disposal of marine sediment are expected to be minimal. Marine sediment disposal should follow the requirements stipulated in ETWB TCW No. 34/2002 Management of Dredged/Excavated Sediment. Mitigation measures to minimise potential environmental impacts are recommended in Section 6.3.7.
6.3.6 Handling and Transportation Arrangement for Waste Disposal
6.3.6.1 Due to the lack of road network near the Project site, marine transportation should be used to deliver and dispose of the waste generated to the designated disposal outlets. For the waste storage arrangements, the collected wastes will temporary stored on barge and suitably contained or covered to avoid the waste from blown away to the sea. Waste storage on land is not required.
6.3.6.2 The surplus inert C&D materials generated from the construction of the Project will be temporarily stored on the barge. They should be properly covered to avoid fugitive dust emission. No barging points and associated conveyor systems will be established and used at the Project site. The inert C&D materials will be delivered to Tseung Kwan O Area 137 Fill Bank by barges or vessels for reuse in other projects.
6.3.6.3 For the non-inert C&D materials generated from the Project, specific areas will be designated on the barges for the segregation of C&D materials into recyclable portion and non-recyclable portion. Recyclable materials such as metal, glass and steel, will be segregated on the barges for off-site recycling. Non-recyclable C&D materials will be collected and placed in bags or bins on the construction barges for temporary storage. Non-recyclable C&D materials in bags or bins will be subsequently either transported by barges/marine vessels directly to West New Territories (WENT) landfill or via Outlying Islands Transfer Facilities (OITF) for final disposal.
General Refuse
6.3.6.4 Recyclable materials from general refuse such as paper, plastic bottles, aluminium cans, will be first segregated on the barges for off-site recycling. General refuse will be collected and placed in bags or bins on the construction barges for temporary storage. General refuse should be properly contained and covered to prevent it from blown away by wind to marine environment. General refuse in bags or bins will be subsequently either transported by barges/marine vessels directly to WENT landfill or via OITF for final disposal.
Marine Sediment
6.3.6.5 Any excavated marine sediment will be loaded to the leak proof container of barges immediately to eliminate leakage during transportation. No overloading of marine sediment or laden water should be allowed. Marine sediments will be transported to designated marine disposal sites for disposal.
Chemical Waste
6.3.6.6 Handling of chemical waste should follow the Waste Disposal (Chemical Waste) (General) Regulation and Code of Practice on the Packaging, Labelling and Storage of Chemical Wastes. Chemical will be packed and held in suitably designed containers to prevent leakage, spillage during handling, storage and transport. The containers should be suitable for the substance they are holding, resistant to corrosion, maintained in good condition and securely closed. They should have a capacity of less than 450L unless the specifications have been approved by EPD. Every container should bear an appropriate label in English and Chinese. Chemical waste will be collected and delivered to Chemical Waste Treatment Centre (CWTC) by a licensed waste collector.
Summary of
Transportation Routings
6.3.6.7 The tentative transportation routings for the disposal of various types of wastes generated during the construction phase are shown in Table 6.8. Nevertheless, no adverse environmental impacts are anticipated due to the transportation of waste with the implementation of appropriate mitigation measures (e.g. using water-tight containers and vessels equipped with mechanical cover).
Table 6.8 Tentative Transportation Routings for Waste Disposal during Construction Phase
|
Type of Waste |
Disposal Outlet |
Tentative
Transportation Routing |
|
Non-recyclable
C&D waste and general refuse |
West New
Territories (WENT) Landfill |
LCW à Crooked Harbour à Mirs
Bay àTathong Channel à Victoria Harbour (àOITF)à Ma Wan Channel à Urmston Road à WENT Landfill |
|
Inert C&D materials |
Tseung Kwan O Area 137
Fill Bank |
LCW à Crooked Harbour à Mirs
Bay àTathong Channel à Tseung
Kwan O Area 137 Fill Bank |
|
Marine sediment |
Designated
Marine Disposal Sites |
LCW à Crooked Harbour àMirs Bay àTathong Channel à Victoria Harbour Ma Wan
Channel à Designated Marine Disposal Sites |
|
Chemical waste |
Chemical Waste
Treatment Centre (CWTC) |
LCW à Crooked Harbour àMirs Bay àTathong Channel à Victoria Harbour àLicensed Chemical Waste
Collector à CWTC |
6.3.6.8 Nevertheless, due to small output of waste of the Project, there will only be a maximum of 2 trips of vessel per working day for waste transportation during the construction phase (for a period between 0800 and 1700 hours). Different types of waste with different disposal outlet would be stockpiled and separated on the barge.
Estimated Waste Quantities
6.3.6.9 A summary of construction waste arising from the Project with recommendation for outlets as well as construction programme for each activity is presented in Table 6.9. The total quantities of each type of construction waste to be generated, reused and disposed of are presented in Table 6.10.
Table 6.9 Summary of Waste Arising with Recommendation for Outlets during Construction Phase
[2] Chemical waste measured by volume (litres) includes spent hydraulic oil & waste fuel, spent lubrication oil & cleaning fluids, and spent solvent. Scrap batteries are measured by weight (kilograms).
[3] As the Project would adopt prefabrication method as far as practicable and does not have significant works which would enable the reuse of C&D materials such as landfilling, on-site reuse of C&D materials is anticipated to be nil.
Table 6.10 Total Quantities for Each Type of Waste to be Generated, Reused and Disposed of during Construction Phase
|
Waste
Type |
Total Amount Generated, m3 [1] |
Total Amount Reused, m3 |
Total Amount Disposed, m3 |
Recommended Outlets |
||
|
On-site [3] |
Off-site |
|||||
|
Inert C&D Materials |
Inert Soft C&D
Materials |
994 |
Nil |
994 |
Nil |
Deliver
to Tseung Kwan O Area 137 Fill Bank for reuse by other projects |
|
Inert
Hard C&D Materials |
69 |
Nil |
69 |
Nil |
Deliver
to Tseung Kwan O Area 137 Fill Bank for reuse by other projects |
|
|
Non-inert C&D Materials |
Non-recyclable C&D Waste |
≤
5 |
Nil |
Nil |
≤
5 |
Disposal
to WENT Landfill |
|
Marine
Sediment |
Category Mp |
109 |
Nil |
Nil |
109 |
Open Sea
Disposal (Dedicated Site) |
|
Category H |
70 |
Nil |
Nil |
70 |
Confined
Marine Disposal |
|
|
Chemical Waste [2] |
Tens of litres/kilograms per month |
N/A |
N/A |
Tens
of litres/kilograms per month |
To be collected and
delivered by a licensed chemical waste collector and disposed of at a
licensed chemical waste treatment and disposal facility |
|
|
General
Refuse |
Non-recyclables
from Work Force |
5.06 tonnes |
N/A |
N/A |
4.1 tonnes |
To be
disposed of at the WENT Landfill |
|
Paper,
Metals, Plastics etc. from Work Force |
N/A |
0.7 tonnes |
N/A |
To be collected by recycler |
||
|
Floating Refuse |
N/A |
N/A |
0.24 tonnes |
To be
disposed of at the WENT Landfill |
||
[1] Volume of inert hard C&D materials, inert soft C&D materials and non-recyclable C&D materials are in-situ bulk volume. Bulk factor of inert hard C&D material is 1.25, while the bulk factor of inert soft C&D materials is 1.11.
[2] Chemical waste measured by volume (litres) includes spent hydraulic oil & waste fuel, spent lubrication oil & cleaning fluids, and spent solvent. Scrap batteries are measured by weight (kilograms).
[3] As the Project would adopt prefabrication method as far as practicable and does not have significant works which would enable the reuse of C&D materials such as landfilling, on-site reuse of C&D materials is anticipated to be “Nil”.
6.3.7.1 The mitigation measures for construction phase are recommended based on the waste management hierarchy in the following orders:
Good Site Practices
6.3.7.2
Adverse waste management
implications are not expected, provided that good site practices are strictly
implemented. The following good site practices are recommended throughout the
construction activities:
·
Nomination of an approved
personnel, such as a site manager, to be responsible for the implementation of
good site practices, arrangements for collection and effective disposal to an
appropriate facility, of all wastes generated at the site;
·
Training of site personnel in site cleanliness, appropriate waste management
procedures and concepts of waste reduction, reuse and recycling;
·
Provision of sufficient
waste disposal points and regular collection for disposal;
·
Appropriate measures to
minimise windblown litter and dust during transportation of waste by either
covering barges or by transporting wastes in enclosed containers; and
Waste
Reduction Measures
6.3.7.3
Amount of waste generation can
be significantly reduced through good management and control. Waste reduction
is best achieved at the planning and design phase, as well as by ensuring the
implementation of good site practices. The following recommendations are
proposed to achieve reduction:
·
Segregate and store different
types of waste in different containers, skip or stockpiles to enhance reuse or
recycling of materials and their proper disposal;
·
Proper storage and site practices to minimise the potential for
damage and contamination of construction materials;
·
Plan and stock
construction materials carefully to minimise amount of waste generated and
avoid unnecessary generation of waste;
·
Sort out demolition debris and excavated materials from demolition
works to recover reusable/recyclable portions (i.e. soil, broken concrete,
metal etc.); and
·
Provide training to
workers on the importance of appropriate waste management procedures, including
waste reduction, reuse and recycling.
6.3.7.4
In addition to the above
measures, specific mitigation measures are recommended for the specific waste
types so as to minimise environmental impacts during
handling, transportation and disposal of waste.
Storage, Collection and Transportation of Waste
6.3.7.5 Storage of waste on site may induce adverse environmental implications if not properly managed. The following recommendation should be implemented to minimise the impacts:
·
Non-inert C&D materials
should be handled and stored well to ensure secure containment of the
materials;
·
Stockpiling area
should be provided with covers and water spraying system to prevent materials
from wind-blown or being washed away; and
·
Different locations
on barges should be designated to stockpile each material to enhance reuse.
6.3.7.6 The collection and transportation of waste from works area to respective disposal sites may also induce adverse environmental impacts if not properly managed. The following recommendation should be implemented to minimise the impacts:
·
Remove waste in timely manner;
·
Employ the vessels
with cover or enclosed containers for waste transportation;
·
Obtain relevant waste disposal
permits from the appropriate authorities;
·
Disposal of waste
should be done at licensed waste disposal facilities; and
·
All
dumping trucks engaged, if required to receive waste from vessels, should be
equipped with GPS or equivalent system for tracking and monitoring of their
travel routings and parking locations by Environmental Team (ET) and
Independent Environmental Checker (IEC) to prohibit illegal dumping and
landfilling of materials; and
·
Keep
record and analysis of data collected by GPS or equivalent system relating to
travel routings and parking locations of dump trucks/vessels engaged on site.
6.3.7.7 In addition to the above measures, other specific mitigation measures on handling the C&D materials and chemical waste generated from construction phase are recommended in the following subsections.
C&D Materials
6.3.7.8 Wherever practicable, C&D materials should be segregated from other wastes to avoid contamination and ensure acceptability at Public Fill Reception Facilities areas or reclamation sites. The following mitigation measures should be implemented in handling the C&D materials:
·
Carry out on-site sorting;
·
Make provisions in the Contract documents to allow and promote the use of
recycled aggregates where appropriate; and
·
Implement a trip-ticket system in accordance
with DEVB TC(W) No. 6/2010 Trip Ticket System for Disposal of Construction and
Demolition Materials, if dumping trucks are
required, for each works
contract to ensure that the disposal of C&D materials is properly documented
and verified.
6.3.7.9 Details of the recommended on-site sorting and reuse of C&D materials are given below:
Sorting of C&D
Materials
6.3.7.11 The Contractor would be responsible for devising a system to work for sorting of C&D materials and promptly remove all sorted and processed material arising from the construction activities to minimise temporary stocking on-site. It is recommended that the system should include the identification of the source of generation, estimated quantity, arrangement for sorting and/ or collection, temporary storage areas, and frequency of collection by recycling contractors or frequency of removal.
Reuse of C&D Materials
Specification of Inert
C&D Materials to be Disposed of off-site
6.3.7.13 In case there are surplus inert C&D materials generated in the Project and are required to be disposed of at the public fill reception facilities, the inert C&D materials should fulfil the following requirements:
· Reclaimed asphalt pavement will not be mixed with other materials when delivered to the public fill reception facilities;
·
Moisture content of inert
C&D materials will be lowered to 25% max. when delivered to the public fill
reception facilities;
·
Inert C&D materials
delivered to the public fill reception facilities should be of a size less than
250mm; and
·
Inert construction waste shall
not be in liquid form such that it can be contained and delivered by water-tight
containers. Inert C&D materials in
liquid form shall be solidified before delivering to the public fill reception
facilities.
6.3.7.14 Nevertheless, the acceptance criteria of inert C&D materials to public fill reception facilities are subject to the fill management authority of CEDD.
Use of Standard Formwork and
Planning of Construction Materials Purchasing
6.3.7.15 Standard formwork should also be used as far as practicable in order to minimise the arising of non-inert C&D materials. The use of more durable formwork (e.g. metal hoarding) or plastic facing should be encouraged in order to enhance the possibility of recycling. The purchasing of construction materials should be carefully planned in order to avoid over ordering and wastage.
General Refuse
6.3.7.16 General refuse should be stored in enclosed bins separately from construction and chemical wastes. Recycling bins should also be placed to encourage recycling. Preferably enclosed and covered areas should be provided for general refuse collection and routine cleaning for these areas should also be implemented to keep areas clean. A waste collector should be employed to remove general refuse on a daily basis. It is expected that such arrangements would minimise potential environmental impacts.
Chemical Waste
6.3.7.18 For those processes which generate chemical waste, it may be possible to find alternatives to eliminate the use of chemicals to reduce the generation quantities or to select a chemical type of less impact on environment, health and safety as far as possible.
6.3.7.19 If chemical wastes are produced at the construction site, the contractors should register with EPD as chemical waste producers. Chemical wastes should be stored in appropriate containers and collected by a licensed chemical waste collector. Chemical wastes (e.g. spent lubricant oil) should be recycled at an appropriate facility as far as possible, whilst the chemical waste that cannot be recycled should be disposed of at either the CWTC, or another licensed facility, in accordance with the Waste Disposal (Chemical Waste) (General) Regulation.
Marine Sediment
6.3.7.20 The total amount of 179 m3 marine sediment is estimated to be excavated during the construction of the Project, among which 109 m3 requires Type 1 – Open Sea Disposal (Confined Space) and 70 m3 requires Type 2 – Confined Marine Disposal.
6.3.7.21 Normally, the contaminated sediment will require to be disposed of at confined contaminated mud pits such as East Sha Chau, while the uncontaminated marine sediment will require open sea disposal, e.g. in South Cheung Chau, Nine Pin, etc. However, no marine dumping should be allowed until all issues on management of excavated sediments have been resolved and all relevant arrangements have been endorsed by the relevant authorities including MFC and EPD.
6.3.7.22 The handling of excavated marine sediment will require proper management in order not to cause environmental impacts and nuisance. Priority should be given to on-site reuse of sediment with low contaminant concentrations. Sediment classified as Category M or H are proposed to be disposed of at respective dumping locations with reference to the contamination level after the biological screening.
6.3.7.23
The
basic requirements and procedures for off-site disposal of dredged/excavated
sediment are specified under the ETWB TCW No. 34/2002 Management of
Dredged/Excavated Sediment. The management of the dredging/excavation, use and
disposal of marine sediment is monitored by the MFC, while the licensing of
marine dumping is the responsibility of the DEP.
6.3.7.24 The excavated sediment from the site would be transferred to barges for subsequent disposal. Release of excavated sediment into the surrounding water should be avoided. It is recommended that the distance between the barge and the sediment excavation points be as short as possible to avoid dropping of sediment to the sea.
6.3.7.25 Possible mitigated measures to handle the sediments are summarised as follows:
· All construction plant and equipment shall be designed and maintained to minimise the risk of silt, sediments, contaminants or other pollutants being released into the water column or deposited in the locations other than designated location.
· All vessels shall be sized such that adequate draft is maintained between vessels and the sea bed at all states of the tide to ensure that undue turbidity is not generated by turbulence from vessel movement or propeller wash.
· Before moving the vessels which are used for transporting marine sediment, excess material shall be cleaned from the decks and exposed fittings of vessels and the excess materials shall never be dumped into the sea except at the approved locations.
· Adequate freeboard shall be maintained on barges to ensure that decks are not washed by wave action.
· The Contractors shall monitor all vessels transporting material to ensure that no dumping outside the approved location takes place. The Contractor shall keep and produce logs and other records to demonstrate compliance and that journeys are consistent with designated locations and copies of such records shall be submitted to the Engineers.
· The Contractors shall comply with the conditions in the dumping licence.
· All bottom dumping vessels (hopper barges) shall be fitted with tight fittings seals to their bottom openings to prevent leakage of material.
· The material shall be placed into the disposal pit by bottom dumping.
· Contaminated marine mud shall be transported by split barge of not less than 750m3 capacity and capable of rapid opening and discharge at the disposal site.
· Discharge shall be undertaken rapidly and the hoppers shall be closed immediately. Material adhering to the sides of the hopper shall not be washed out of the hopper and the hopper shall remain closed until the barge returns to the disposal site.
6.3.8 Residual Waste Management Implications
6.3.8.1 With the implementation of recommended mitigation measures for the handling, transportation and disposal of the identified waste, adverse residual waste management implications are not anticipated for the construction phase.
6.4.1 Assessment Methodology
6.4.1.1 The assessment of waste management implications has been undertaken in accordance with Annexes 7 and 15 of the TM-EIAO and the EIA Study Brief No. ESB-305/2017. The waste management hierarchy comprising avoidance, minimisation, recycling/ reuse, and disposal has also been adopted for the assessment.
6.4.1.2 Prior to considering the disposal options for various types of wastes, opportunities for reducing waste generated, on-site or off-site reuse and recycling have been evaluated. After considering all the opportunities for reducing waste generation and maximising reuse, the types and quantities of the remaining wastes required to be disposed of have been estimated and the disposal options for each type of wastes have been described. The potential environmental impacts from the management of wastes have been assessed and relevant mitigation measures have been proposed.
6.4.2 Identification and Evaluation of Waste Management Implications
6.4.2.1 The Project only involves pier improvement works for the existing pier, and no increment of Kaito services frequency would be provided after the pier improvement works. Hence, the Project will not induce any additional municipal solid waste from additional visitors and pier users during the operational phase. Sufficient number of trash bins and recycling bins have already been provided for the collection of general refuse generated by visitors and pier users along the existing footpath to Lai Chi Wo. No bin will be required to be provided in the Lai Chi Wo Pier as no general refuse is anticipated by the Project during the operational phase.
6.4.2.2 The accumulation of floating refuse at the nearby water is not anticipated as the foundation of the pier is made of pile columns, which would allow circulation of sea water and avoid trapping of floating refuse.
6.4.2.3 Therefore, it is anticipated that there would not be significant increase in the amount of general refuse generated after the pier improvement works. With the implementation of the above-mentioned recommended practices, no adverse waste management implications are anticipated.
6.4.3 Mitigation Measures
General Refuse
6.4.3.1 Sufficient number of trash bins and recycling bins have already been provided for the collection of general refuse generated by visitors and pier users along the existing footpath to Lai Chi Wo. No bin will be provided as no general refuse is anticipated by the Project during the operational phase. Nevertheless, recycling containers are recommended to be provided at suitable locations to encourage recycling of waste such as aluminium cans and plastics.
6.4.4 Residual Waste Management Implications
6.4.4.1 With the implementation of recommended mitigation measures for the handling, transportation and disposal of the identified waste, adverse residual waste management implications are not anticipated for the operational phase.
6.5.1 Construction Phase
6.5.1.1
Potential waste management
implications from the generation of waste during the construction phase have
been evaluated. Measures, including the opportunity for on-site sorting,
reusing C&D materials etc., are devised in the construction methodology to
minimise the surplus materials to be disposed of to a landfill. Recommendations
have been made for implementation by the Contractor during the construction
period to minimise waste generation and off-site disposal.
6.5.1.2
It is estimated that 994m3
of inert soft C&D materials would be generated in which all would be reused
off-site. Besides, 69m3 of
inert hard C&D materials would be generated. The total inert C&D
materials (includes inert soft C&D materials and inert hard C&D
materials) to be generated would be 1,063m3 in which all of them
would be delivered to public fill bank for reuse in other projects. In
addition, ≤5m3
non-recyclable C&D waste is anticipated during the removal of temporary
pier and will be delivered to WENT landfill for final disposal. Furthermore, it is estimated
that 179m3 of marine sediment to be disposed of at dedicated marine
disposal sites; 109m3 of which belongs to
Category Mp required Type 1 – Open Sea
(Dedicated Sites) Disposal; whilst the remaining 70m3 of which
belongs to Category H required Type 2 – Confined Marine Disposal.
6.5.1.3 It is estimated that in total 5.06 tonnes of general refuse, paper, metals, plastics, etc. would be generated from work force, in which 0.7 tonnes would be collected by recycler for offsite reuse and the remaining 4.36 tonnes would be disposed of at WENT Landfill. In addition, it is estimated 0.24 tonnes of floating refuse would be collected during the construction phase to be disposed of at WENT Landfill. Tens of litres / kilograms of chemical waste would be generated per month and it would be recycled by licensed facility as far as possible. The remaining chemical waste would be disposed of at CWTC.
6.5.2 Operational Phase
6.5.2.1 The types of waste that would be generated during the operational phase would be general refuse from the pier users. The Project itself does not intend to increase Kaito services. Hence, it will not induce any additional general refuse from additional visitors and pier users during the operational phase. Sufficient number of trash bins and recycling bins have already been provided for the collection of general refuse generated by visitors and pier users along the existing footpath to Lai Chi Wo. No bin will be required to be provided in the Lai Chi Wo Pier as no general refuse is anticipated by the Project during the operational phase. Adverse waste management implications are not anticipated.